Transistors function as switching devices and driving devices to control and drive a flat panel display, such as, a liquid crystal display, an electroluminescent display, or the like. Currently, the widely used transistors in an array substrate of the liquid crystal display are thin film transistors in a bottom-gate, bottom-contact configuration and thin film transistors in a bottom-gate, top-contact configuration.
As shown in FIG. 1, a gate electrode 1 of a thin film transistor in the bottom-gate, bottom-contact configuration is fabricated on a substrate 3, on top of the gate electrode 1 is a gate insulation layer 4, and source and drain electrodes 2 are located between the gate insulation layer 4 and a semiconductor thin film 5. Boundaries of the source and drain electrodes 2 in this structure may affect the deposition of the semiconductor thin film 5, so that molecular arranging regularity of the semiconductor thin film 5 is degraded. Thus, the transportation of its carriers is disadvantageously affected, so that properties of the device are degraded, and in turn, the quality of the array substrate is affected.
As shown in FIG. 2, a gate electrode 1 of a thin film transistor in the bottom-gate, top-contact configuration is fabricated on a substrate 3 likewise, on top of the gate electrode 1 is a gate insulation layer 4, a semiconductor thin film 5 is fabricated over the gate insulation layer 4, and metal electrodes are further grown on the semiconductor thin film 5 to form source and drain electrodes 2. The manufacturing process of the source and drain electrodes 2 in this structure is largely restricted, and the organic semiconductor thin film which has already have good arranging regularity may be damaged upon fabrication of the source and drain electrodes 2. Generally, the electrodes can only be formed by means of thermal evaporation, and the difficulty of production is relatively high.
As for the existing array substrates with thin film transistors in the bottom-gate, bottom-contact configuration and the bottom-gate, top-contact configuration, photolithography and masking are needed to be performed for many times during fabrication, thus the fabricating process is tedious, and the production costs are relatively high.